Wobble on front end

[Kibokojoe]

Pulled tires on the front end tonight to check a number of components. When braking moderately to hard at 40 mph and higher the front end shutters. The first thing we did was replace the front tires with a spare I have in the garage. No change. Then we pulled the brake pads and calipers. I visually inspected the rotors and they appear fairly smooth. Brake pad look good. Tested each caliper with a Caliper pins are in great shape and I applied some brake lubricant on the pins when reinstalling. Calipers moved smoothly. Reinstalled the tires and looked for front end parts movement. The only movement I found was in the steering box. All other components tierod ends etc appear to be solid. I even checked for slop in the wheel bearing they appear to be in fine shape. Still have wobble. What do I check now?

[632 Regal]

caliper pins should be assembled DRY. If you have any play in the front end you will get a shimmy due to the design.

You also could have bad thrust arm bushings, that alone can do it but since you already see play in the steering fix that first.

If you do the bushings use the M5 bushings not that other weak ass crap IE: 750 bushes.

[Kibokojoe]

Interesting I was told by someone on this site to use a special lube on the caliper pins. I don't think it is so much a lubricant as it keeps the pins free of crap building up on them. I will check out the thrust arm bushings. As far as free play in the steering box. I didn't think you could fix this? Is there an adjustment?

[Tiger]

Thrust arm... bushing and or ball joint is the most common reason.

Other reason is...

lower control arm
warped rotor

[e34.535i.sport]

I had a similar thing... +1 on thrust bushes or balljoints... Check the balljoints by jacking up & leaving wheel on... Put your hands at 9o'clock and 3o'clock and wiggle the wheel - if there's play then the balljoints may be gone.

I changed my thrust bushes and it solved the problem and tightened up the feel of the steering around corners... Here's how:
http://www.bimmernut.com/forum/showthread.php?t=39481&highlight=thrust+arm+bush+replacement

[Kibokojoe]

I am leaning towards this solution. I am looking for the M5 bushing for replacement. Yes I jacked up the car and pulled on the both wheels at the same time both wheels at front and both at the back, if you can understand what I am saying. Linkage seemed tight, all I got was slack in the steering box.

[Kibokojoe]

Ok looks like I found out the major problem. The left caliper piston was not sliding as easily as the right caliper piston. After working the calipers in and out several times they now slide evenly. There is still a slight wobbling but every so small now. I agree I will need to replace the control arm bushings and probably the control arm ball joints too. Now I need to find the M5 bushings. Does anyone provide the control arm with the M5 bushings already installed?

[632 Regal]

I know that BMAparts supply it that way autohauz may also but I never checked, you will have to call to get an answer cause its not available on either site that way. The M5 bushings still have not went bad on me after 3 years! Considering I can tear a stock and 750 up on a test run the M5s are monsters. Once you compare them you will too be convinced.


Does anyone provide the control arm with the M5 bushings already installed?

[Robin-535im]

What you mention is the classic thrust arm shimmy... seen it oh-so many times before - in fact, I need new bushings right now myself. Bushings last a few years at best.

I wouldn't spend any money on rotors/calipers until you get new thrust arms in there, and torque them under load to avoid premature wear.

CW in the past was to go with the 750's, but the M5's are supposedly as good or better. I think Winfred chooses the M5's as replacements IIRC.

HTH

- Robin

[Scott C]

I think you have the answers - but i will post a free one that is worth checking and takes about 1 hour.

Tighten the big mother column nut that controls part of the telescoping steering assembly (assuming you have this feature). When this is not fully tight, the front steering system is essentially disconnected (backlash) from driver input to some small extent which allows oscillation to occur. Any vibration induced by the braking (warpage, etc) is amplified by this backlash.

To tighten, it requires you to pull the front panel off (under the cluster), then the panel above driver's feet to access (same as getting to brake switch).

You WON'T go wrong with M5 bushings as regal has said...

Scott

[632 Regal]

Shoot I forgot all about the nut behind the wheel!!! Mine was way loose after I cracked it free, almost a turn and a half to get it snugged back up.
I think you have the answers - but i will post a free one that is worth checking and takes about 1 hour.

Tighten the big mother column nut that controls part of the telescoping steering assembly (assuming you have this feature). When this is not fully tight, the front steering system is essentially disconnected (backlash) from driver input to some small extent which allows oscillation to occur. Any vibration induced by the braking (warpage, etc) is amplified by this backlash.

To tighten, it requires you to pull the front panel off (under the cluster), then the panel above driver's feet to access (same as getting to brake switch).

You WON'T go wrong with M5 bushings as regal has said...

Scott

[Kibokojoe]

I will definitely try this